The Admissions Office usually requires the following material to be a part of your application packet:
1. Transcripts from postsecondary institutions
2. Scores from standardized test (e.g. GRE, GMAT, TOEFL)
3. Recommendation letters
4. Statement of purpose
5. Application fee
6. Supplementary materials (e.g. artwork, writing samples for some courses)
How you can make your application stand out
In addition to the items specifically requested by the university, you can send additional material that highlights your achievements. For example, you can send a one-page resume that lists any awards, publications and extra-curricular achievements.
Also, it is advisable that your application reaches at least two weeks before the application deadline. As the deadline approaches, admission offices are usually flooded with mail. The earlier your application reaches its destination, the higher chance it might have of being properly filed and receiving attention from the Admission Committee. Usually, applications are reviewed in the order in which they are received. Decisions to award financial aid to prospective students are sometimes made early on, and you may benefit if your application is higher up on the stack!
Important points to remember
Once you have decided which program you want to apply to, visit the websites of both the University and the Department to which you are applying. In many cases, it is required to send separate applications to each of them (sometimes, even a separate fee may be required).
You must strictly follow guidelines on whether your application materials can be pinned/ stapled. Ignoring these may delay the processing of your application. It is generally a good idea to put together your application such that the items are in the same order as requested. Any additional material that you enclose should be placed towards the end.
Some universities accept online payments for application fees. In case you are planning to use this option, make sure that the credit card you are going to use allows payments in US Dollars.